Crystals
Garnet
Garnet mineral family X3Y2(SiO4)3 Cubic crystal system Mohs approximately 6.5–7.5 No cleavage Red, orange, yellow, green, violet, black Tsavorite and demantoid Spessartine and hessonite Garnet: The Mineral Family Beyond Red...
Garnet
Garnet mineral family X3Y2(SiO4)3 Cubic crystal system Mohs approximately 6.5–7.5 No cleavage Red, orange, yellow, green, violet, black Tsavorite and demantoid Spessartine and hessonite Garnet: The Mineral Family Beyond Red...
Labradorite
Plagioclase feldspar Approximately An50–An70 (Ca,Na)(Al,Si)4O8 Triclinic crystal system Mohs approximately 6–6.5 Two cleavages near 90 degrees Directional labradorescence Blue, green, gold, orange, and violet flash Spectrolite and rainbow moonstone Labradorite:...
Labradorite
Plagioclase feldspar Approximately An50–An70 (Ca,Na)(Al,Si)4O8 Triclinic crystal system Mohs approximately 6–6.5 Two cleavages near 90 degrees Directional labradorescence Blue, green, gold, orange, and violet flash Spectrolite and rainbow moonstone Labradorite:...
Lava
Informal rock name Usually vesicular basalt or scoria Extrusive igneous material Frozen volcanic gas bubbles Black, charcoal, brown, and red Vesicular or amygdaloidal texture Landscape, architectural, and lapidary use Rock...
Lava
Informal rock name Usually vesicular basalt or scoria Extrusive igneous material Frozen volcanic gas bubbles Black, charcoal, brown, and red Vesicular or amygdaloidal texture Landscape, architectural, and lapidary use Rock...
Meteorite
Extraterrestrial geological material Mostly fragments of asteroids Stony, stony-iron, and iron groups Oldest solids approximately 4.567 billion years Fusion crust and atmospheric ablation Iron-nickel metal in many types Chondrules, olivine,...
Meteorite
Extraterrestrial geological material Mostly fragments of asteroids Stony, stony-iron, and iron groups Oldest solids approximately 4.567 billion years Fusion crust and atmospheric ablation Iron-nickel metal in many types Chondrules, olivine,...
Kyanite
Aluminum silicate polymorph Al2SiO5 Triclinic crystal system High-pressure metamorphic mineral Strong directional hardness Perfect and good cleavage Blue, green, gray, white, black Rare orange variety Kyanite: Blue Blades Shaped by...
Kyanite
Aluminum silicate polymorph Al2SiO5 Triclinic crystal system High-pressure metamorphic mineral Strong directional hardness Perfect and good cleavage Blue, green, gray, white, black Rare orange variety Kyanite: Blue Blades Shaped by...
Ruby
Red corundum Al2O3 with Cr3+ Trigonal crystal system Mohs 9 No true cleavage Purplish-red to orangey-red pleochroism Marble, amphibolite, and basalt-associated deposits Rutile silk and six-ray stars Natural and laboratory-grown...
Ruby
Red corundum Al2O3 with Cr3+ Trigonal crystal system Mohs 9 No true cleavage Purplish-red to orangey-red pleochroism Marble, amphibolite, and basalt-associated deposits Rutile silk and six-ray stars Natural and laboratory-grown...